I've gotta say, this article took all the enjoyment out of the subject. Not that the work isn't worthwhile, but if you're going to go to the philosophers to understand what is meant by 'enjoyment' (and you should) you could probably do better than prickly analytics like Perry or Warner (Perry: enjoyment is "non-evaluative, non-conative pro-attitude toward some actual object for what it is in itself, which object is a present doing, undergoing, or experiencing on the part of the subject or is something which is intimately connected with a present doing, undergoing, or experience on his part." - philosophy is full of stuff like that, which is why I no longer contribute to the philosophical literature). The diagram of enjoyment in Figure 1 is worth while, though. You can stop reading once you read the 'Method' heading; while it was a good paper up to there (I was just kidding about it eliminating any enjoyment) the remainder of the paper is devoted to a 'study' - how many times do I have to say this? Surveying five of your friends (or five of anything!) is not empirical science.